TORONTO, Aug 26 (Reuters) - Canada’s main stock index rose on Friday, led by energy and mining stocks as oil and gold prices gained after a speech by Federal Reserve Chair Janet Yellen viewed as supportive of a U.S. interest rate increase.

The most influential movers on the index were gold stocks, including Barrick Gold, which rose 2.3 percent to C$24.2, and Franco Nevada Corp, up by the same margin to C$95.81.

The case for raising U.S. interest rates has strengthened in recent months because of improvements in the U.S. labor market and expectations for moderate economic growth, Yellen said.

The materials group, which includes precious and base metals, miners and fertilizer companies, added 2.2 percent, while energy stocks advanced 1.2 percent as a lower U.S. dollar also helped support energy prices.

U.S. crude prices were up 1.7 percent to $48.11 a barrel and Canadian Natural Resources Ltd rose nearly 1.0 percent to C$41.78.

Toronto-Dominion Bank has made changes to its mortgage underwriting practices in recent years, its chief risk officer said on Thursday, potentially making it more resilient if house prices fall in Vancouver and Toronto. (Reporting by Fergal Smith; Editing by Dan Grebler)